Azithromycin suppresses Th1- and Th2-related chemokines IP-10/MDC in human monocytic cell line

The possible effect of topically applied azithromycin and moxifloxacin on the alleviation of uveitis

PURPOSE

To investigate the inhibitory effect of topically administered azithromycin (AZM), and moxifloxacin (MXF) against tumor necrosis factor-α (TNF-α) production in a rat model of endotoxin-induced uveitis (EIU).

METHODS

Thirty-six Wistar albino rats were divided into 6 equal groups. Groups 1, 2 and 3 were determined as sham, control group for topical AZM application and control group for topical MXF application, respectively. Sterile saline, topical AZM 1.5%, and topical MXF 0.5% were instilled 5 times daily for totally 6 days on both eyes of the rats in Group 4, Group 5, and Group 6, before and after inducing EIU by intravitreal injections of lipopolysaccharide, respectively. At 24 h after intravitreal injections, aqueous humor was collected from both eyes of each rat for the assessment of TNF-α concentration. Also, density of nuclear factor kappa B (NF-κB) in ciliary body, and the number of cells infiltrating the posterior segment of EIU rat eyes was assessed in one eye of each rat.

RESULTS

There was a significant reduction in mean aqueous humor concentration of TNF-α in EIU rats pretreated with topical AZM in comparison with those pretreated with sterile saline (139 ± 38.6 in Group 4 vs. 72 ± 12.6 in Group 5, p = 0.006). There was also a marked decrease in mean aqueous humor concentration of TNF-α in EIU rats pretreated with topical MXF (139 ± 38.6 in Group 4 vs.86.1 ± 35.5 in Group 6, p = 0.025). Also, evident suppressions were determined in mean density of NF-κB, and in mean number of cells in EIU rats pretreated either with topical AZM, or topical MXF.

CONCLUSIONS

Topically applied AZM or MXF may be beneficial in the suppression of TNF-α production in aqueous humor.

Immunomodulatory role of azithromycin: Potential applications to radiation-induced lung injury

Radiation-induced lung injury (RILI) including radiation-induced pneumonitis and radiation-induced pulmonary fibrosis is a side effect of radiotherapy for thoracic tumors. Azithromycin is a macrolide with immunomodulatory properties and anti-inflammatory effects. The immunopathology of RILI that results from irradiation is robust pro-inflammatory responses with high levels of chemokine and cytokine expression. In some patients, pulmonary interstitial fibrosis results usually due to an overactive immune response. Growing clinical studies recently proposed that the anti-inflammatory and immunomodulatory effects of azithromycin may benefit patients with acute lung injury. It has been shown potential benefits for patients with RILI in preclinical studies. Azithromycin has a variety of immunomodulatory effect to improve the process of disease, including inhibition of pro-inflammatory cytokines production participating in the regulatory function of macrophages, changes in autophagy, and inhibition of neutrophil influx. We review the published evidence of mechanisms of azithromycin, and focus on the potential effect of azithromycin on the immune response to RILI.

Azithromycin Attenuates Bleomycin-Induced Pulmonary Fibrosis Partly by Inhibiting the Expression of LOX and LOXL-2

Pulmonary fibrosis (PF) is a chronic and progressive process of tissue repair. Azithromycin (AZM) may be beneficial for the treatment of PF because AZM has anti-inflammatory and immune regulatory roles and inhibits remodeling, but the mechanism is not entirely clear. In this study, we established a mouse PF model induced by bleomycin (BLM) and primary mouse lung fibroblasts stimulated by transforming growth factor (TGF)-β1 to explore the possible mechanisms of AZM in PF. Results showed that AZM reduces mortality and lung inflammation and attenuates BLM-induced PF in mice. AZM effectively reduced the expression of α-smooth muscle actin (SMA) and type I collagen. Meanwhile, expression of lysyl oxidase (LOX) and lysyl oxidase-like protein (LOXL)-2 in the lung tissue of mice after AZM treatment was significantly lower than in the BLM group. In addition, this study found that AZM significantly inhibits the TGF-β1/Smad and JNK/c-Jun signaling pathways in vivo, and expression of a-SMA, type I collagen, LOX and LOXL-2 in the lung tissue of mice treated with AZM was significantly lower than that in the BLM group. In vitro, AZM also effectively inhibited type I collagen, LOX, LOXL-2 and JNK-c-Jun signaling pathways in TGF-β1-stimulated primary mouse fibroblasts, and this effect was similar to that of a JNK-specific inhibitor (SP600125). In conclusion, AZM effectively attenuated BLM-induced PF in mice, which may play a role by partially inhibiting the JNK/c-Jun and TGF-β1/Smad signaling pathways and reducing production of LOX and LOXL2.

Azithromycin modulates Teff/Treg balance in retinal inflammation via the mTOR signaling pathway

Uveitis is one of the most common blindness-causing ocular disorders. Due to its complicated pathogenesis, the treatment of uveitis has been widely recognized as a challenge for ophthalmologists. Recently, the anti-inflammatory properties of the antibiotic Azithromycin (AZM) have been reported. However, the therapeutic effects of Azithromycin in experimental autoimmune uveitis (EAU), a representative model of human AU, have not been elucidated till date. We conducted this study to examine the therapeutic effects and potential mechanisms of Azithromycin in EAU. We observed that Azithromycin significantly attenuated retinal inflammation in EAU mice at day 14 after immunization along with a significantly decreased inflammatory cell infiltration and cytokine production in the retina. Furthermore, we observed that Azithromycin increased the number of regulatory T cells (Treg) and decreased the number of effector T cells (Teff) in both the draining lymph nodes and spleen of EAU mice. Additionally, Azithromycin suppressed the proliferation and activation of CD4 + T cells, and induced the apoptosis of CD4 + CD44 + memory T and CD4 + CXCR3 + Th1 cells. Mechanistically, we proved that Azithromycin could regulate Teff/Treg balance by inhibiting the phosphorylation of S6 ribosomal protein, a downstream target of mammalian target of rapamycin (mTOR). Together, our findings revealed that Azithromycin alleviated EAU by regulating the Teff/Treg balance through the mTOR signaling pathway, suggesting that Azithromycin could be a promising therapeutic candidate for AU.

Cytometric analysis of patients with COVID-19: what is changed in the second wave?

Background

Coronavirus disease 2019 (COVID-19) pandemic had a 1st wave in Europe from March to May 2020 and a 2nd wave since September 2020. We previously studied 35 hospitalized COVID-19 patients of the 1st wave demonstrating a cytokine storm and the exhaustion of most lymphocyte subpopulations. Herein, we describe the results obtained from COVID-19 patients of the 2nd wave.

Methods

We analyzed interleukin (IL)-6 by human-specific enzyme-linked immunosorbent assay and a large set of lymphocyte subpopulations by flow cytometry in 274 COVID-19 patients hospitalized from September 2020 to May 2021.

Results

Patients of 2nd wave compared with those of 1st wave showed lower serum IL-6 levels and a higher number of B and most T lymphocyte subpopulations in advanced stages, in relation with the age and the gender. On the other hand, we observed in 2nd wave patients: (i) a reduction of most lymphocyte subpopulations at mild and moderate stages; (ii) a reduction of natural killer cells and T regulatory cells together with a higher number of activated T helper (TH) 17 lymphocytes in all stages, which were mainly related to steroid and azithromycin therapies before hospitalization.

Conclusions

COVID-19 had a less severe impact in patients of the 2nd wave in advanced stages, while the impact appeared more severe in patients of mild and moderate stages, as compared with 1st wave patients. This finding suggests that in COVID-19 patients with milder expression at diagnosis, steroid and azithromycin therapies appear to worsen the immune response against the virus. Furthermore, the cytometric profile may help to drive targeted therapies by monoclonal antibodies to modulate specific IL/lymphocyte inhibition or activation in COVID-19 patients.

COVID-19 challenges and its therapeutics

COVID-19, an infectious disease, has emerged as one of the leading causes of death worldwide, making it one of the severe public health issues in recent decades. nCoV, the novel SARS coronavirus that causes COVID-19, has brought together scientists in the quest for possible therapeutic and preventive measures. The development of new drugs to manage COVID-19 effectively is a challenging and time-consuming process, thus encouraging extensive investigation of drug repurposing and repositioning candidates. Several medications, including remdesivir, hydroxychloroquine, chloroquine, lopinavir, favipiravir, ribavirin, ritonavir, interferons, azithromycin, capivasertib and bevacizumab, are currently under clinical trials for COVID-19. In addition, several medicinal plants with considerable antiviral activities are potential therapeutic candidates for COVID-19. Statistical data show that the pandemic is yet to slow down, and authorities are placing their hopes on vaccines. Within a short period, four types of vaccines, namely, whole virus, viral vector, protein subunit, and nucleic acid (RNA/DNA), which can confer protection against COVID-19 in different ways, were already in a clinical trial. SARS-CoV-2 variants spread is associated with antibody escape from the virus Spike epitopes, which has grave concerns for viral re-infection and even compromises the effectiveness of the vaccines. Despite these efforts, COVID-19 treatment is still solely based on clinical management through supportive care. We aim to highlight the recent trends in COVID-19, relevant statistics, and clinical findings, as well as potential therapeutics, including in-line treatment methods, preventive measures, and vaccines to combat the prevalence of COVID-19.

Sputum TNF markers are increased in neutrophilic and severe asthma and are reduced by azithromycin treatment

BACKGROUND

The AMAZES randomized controlled trial demonstrated that long-term low-dose azithromycin treatment reduces exacerbations of poorly controlled asthma, but the therapeutic mechanisms remain unclear. Dysregulation of the inflammatory tumour necrosis factor (TNF) pathway is implicated in asthma and could be suppressed by azithromycin. We aimed to determine the inflammatory and clinical associations of soluble TNF signalling proteins (TNF receptors [TNFR] 1 and 2, TNF) in sputum and serum, and to test the effect of 48 weeks of azithromycin vs placebo on TNF markers.

METHODS

Sputum supernatant and serum TNFR1, TNFR2 (n = 142; 75 azithromycin-treated, 67 placebo-treated) and TNF (n = 48; 22 azithromycin-treated, 26 placebo-treated) were measured by ELISA in an AMAZES trial sub-population at baseline and end of treatment. Baseline levels were compared between sputum inflammatory phenotypes, severe/non-severe asthma and frequent/non-frequent exacerbators. Effect of azithromycin on markers was tested using linear mixed models.

RESULTS

Baseline sputum TNFR1 and TNFR2 were significantly increased in neutrophilic vs non-neutrophilic asthma phenotypes, while serum markers did not differ. Sputum TNFR1 and TNFR2 were increased in severe asthma and correlated with poorer lung function, worse asthma control and increasing age. Serum TNFR1 was also increased in severe asthma. Sputum and serum TNFR2 were increased in frequent exacerbators. Azithromycin treatment significantly reduced sputum TNFR2 and TNF relative to placebo, specifically in non-eosinophilic participants.

CONCLUSIONS

We demonstrate dysregulation of TNF markers, particularly in the airways, that relates to clinically important phenotypes of asthma including neutrophilic and severe asthma. Suppression of dysregulated TNF signalling by azithromycin could contribute to its therapeutic mechanism.

Pathogenesis and Management of COVID-19

COVID-19, occurring due to SARS-COV-2 infection, is the most recent pandemic disease that has led to three million deaths at the time of writing. A great deal of effort has been directed towards altering the virus trajectory and/or managing the interactions of the virus with its subsequent targets in the human body; these interactions can lead to a chain reaction-like state manifested by a cytokine storm and progress to multiple organ failure. During cytokine storms the ratio of pro-inflammatory to anti-inflammatory mediators is generally increased, which contributes to the instigation of hyper-inflammation and confers advantages to the virus. Because cytokine expression patterns fluctuate from one person to another and even within the same person from one time to another, we suggest a road map of COVID-19 management using an individual approach instead of focusing on the blockbuster process (one treatment for most people, if not all). Here, we highlight the biology of the virus, study the interaction between the virus and humans, and present potential pharmacological and non-pharmacological modulators that might contribute to the global war against SARS-COV-2. We suggest an algorithmic roadmap to manage COVID-19.

Azithromycin: Immunomodulatory and antiviral properties for SARS-CoV-2 infection

Azithromycin, a member of the macrolide family of antibiotics, is commonly used to treat respiratory bacterial infections. Nevertheless, multiple pharmacological effects of the drug have been revealed in several investigations. Conceivably, the immunomodulatory properties of azithromycin are among its critical features, leading to its application in treating inflammatory diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Additionally, azithromycin may directly inhibit viral load as well as its replication, or it could demonstrate indirect inhibitory impacts that might be associated with the expression of antiviral genes. Currently, coronavirus disease 2019 (COVID-19) is an extra urgent issue affecting the entire world, and it is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Acute respiratory distress syndrome (ARDS), which is associated with hyper inflammation due to cytokine release, is among the leading causes of death in COVID-19 patients with critical conditions. The present paper aims to review the immunomodulatory and antiviral properties of azithromycin as well as its potential clinical applications in the management of COVID-19 patients.

Is there a need to widely prescribe antibiotics in patients hospitalized with COVID-19?

BACKGROUND

Debate continues regarding the usefulness and benefits of wide prescription of antibiotics in patients hospitalized with coronavirus disease 2019 (COVID-19).

METHODS

All patients hospitalized in the Infectious Diseases Department, Dijon University Hospital, Dijon, France between 27 February and 30 April 2020 with confirmed COVID-19 were included in this study. Clinical, biological and radiological data were collected, as well as treatment and outcome data. An unfavourable outcome was defined as death or transfer to the intensive care unit. Patient characteristics and outcomes were compared between patients who did and did not receive antibiotic therapy using propensity score matching.

FINDINGS

Among the 222 patients included, 174 (78%) received antibiotic therapy. The univariate analysis showed that patients who received antibiotic therapy were significantly older, frailer and had more severe presentation at admission compared with patients who did not receive antibiotic therapy. Unfavourable outcomes were more common in patients who received antibiotic therapy [hazard ratio (HR) 2.94, 95% confidence interval (CI) 1.07-8.11; P = 0.04]. Multi-variate analysis and propensity score matching indicated that antibiotic therapy was not significantly associated with outcome (HR 1.612, 95% CI 0.562-4.629; P = 0.37).

CONCLUSION

Antibiotics were frequently prescribed in this study and this was associated with more severe presentation at admission. However, antibiotic therapy was not associated with outcome, even after adjustment. In line with recent publications, such data support the need to streamline antibiotic therapy in patients with COVID-19.

Pharmacological basis for the potential role of Azithromycin and Doxycycline in management of COVID-19

A novel corona virus SARS-CoV-2 has led to an outbreak of the highly infectious pandemic COVID-19 complicated viral pneumonia. Patients with risk factors frequently develop secondary infections where the role of appropriate antibiotics is mandatory. However, the efforts of drug repurposing lead to recognizing the role of certain antibiotics beyond the management of infection. The current review provided the detailed antiviral, immunomodulatory effect, unique pharmacokinetic profile of two antibiotics namely azithromycin (AZ) and doxycycline (DOX). It summarizes current clinical trials and concerns regarding safety issues of these drugs. Azithromycin (AZ) has amazing lung tissue access, wide range antibacterial efficacy, conceivable antiviral action against COVID-19. It also showed efficacy when combined with other antiviral drugs in limited clinical trials, but many clinicians raise concerns regarding cardiovascular risk in susceptible patients. DOX has a considerable role in the management of pneumonia, it has some advantages including cardiac safety, very good access to lung tissue, potential antiviral, and immunomodulation impact by several mechanisms. The pharmacological profiles of both drugs are heightening considering these medications for further studies in the management of COVID-19.

Prevention and treatment of COVID-19: Focus on interferons, chloroquine/hydroxychloroquine, azithromycin, and vaccine

The ongoing pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has drawn the attention of researchers and clinicians from several disciplines and sectors who are trying to find durable solutions both at preventive and treatment levels. To date, there is no approved effective treatment or vaccine available to control the coronavirus disease-2019 (COVID-19). The preliminary in vitro studies on viral infection models showed potential antiviral activities of type I and III interferons (IFNs), chloroquine (CQ)/hydroxychloroquine (HCQ), and azithromycin (AZM); however, the clinical studies on COVID-19 patients treated with CQ/HCQ and AZM led to controversies in different regions due to their adverse side effects, as well as their combined treatment could prolong the QT interval. Interestingly, the treatment with type I IFNs showed encouraging results. Moreover, the different preliminary reports of COVID-19 candidate vaccines showcase promising results by inducing the production of a high level of neutralizing antibodies (NAbs) and specific T cell-mediated immune response in almost all participants. The present review aims to summarize and analyze the recent progress evidence concerning the use of IFNs, CQ/HCQ, and AZM for the treatment of COVID-19. The available data on immunization options to prevent the COVID-19 are also analyzed with the aim to present the promising options which could be investigated in future for sustainable control of the pandemic.

Interferon-inducer antivirals: Potential candidates to combat COVID-19

Coronavirus disease 2019 (COVID-19) is an infective disease generated by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given the pandemic urgency and lack of an effective cure for this disease, drug repurposing could open the way for finding a solution. Lots of investigations are ongoing to test the compounds already identified as antivirals. On the other hand, induction of type I interferons are found to play an important role in the generation of immune responses against SARS-CoV-2. Therefore, it was opined that the antivirals capable of triggering the interferons and their signaling pathway, could rationally be beneficial for treating COVID-19. On this basis, using a database of antivirals, called drugvirus, some antiviral agents were derived, followed by searches on their relevance to interferon induction. The examined list included drugs from different categories such as antibiotics, immunosuppressants, anti-cancers, non-steroidal anti-inflammatory drugs (NSAID), calcium channel blocker compounds, and some others. The results as briefed here, could help in finding potential drug candidates for COVID-19 treatment. However, their advantages and risks should be taken into account through precise studies, considering a systemic approach. Even though the adverse effects of some of these drugs may overweight their benefits, considering their mechanisms and structures may give a clue for designing novel drugs in the future. Furthermore, the antiviral effect and IFN-modifying mechanisms possessed by some of these drugs might lead to a synergistic effect against SARS-CoV-2, which deserve to be evaluated in further investigations.

Pharmaco-Immunomodulatory Therapy in COVID-19

The severe acute respiratory syndrome coronavirus 2 associated coronavirus disease 2019 (COVID-19) illness is a syndrome of viral replication in concert with a host inflammatory response. The cytokine storm and viral evasion of cellular immune responses may play an equally important role in the pathogenesis, clinical manifestation, and outcomes of COVID-19. Systemic proinflammatory cytokines and biomarkers are elevated as the disease progresses towards its advanced stages, and correlate with worse chances of survival. Immune modulators have the potential to inhibit cytokines and treat the cytokine storm. A literature search using PubMed, Google Scholar, and ClinicalTrials.gov was conducted through 8 July 2020 using the search terms ‘coronavirus’, ‘immunology’, ‘cytokine storm’, ‘immunomodulators’, ‘pharmacology’, ‘severe acute respiratory syndrome 2’, ‘SARS-CoV-2’, and ‘COVID-19’. Specific immune modulators include anti-cytokines such as interleukin (IL)-1 and IL-6 receptor antagonists (e.g. anakinra, tocilizumab, sarilumab, siltuximab), Janus kinase (JAK) inhibitors (e.g. baricitinib, ruxolitinib), anti-tumor necrosis factor-α (e.g. adalimumab, infliximab), granulocyte–macrophage colony-stimulating factors (e.g. gimsilumab, lenzilumab, namilumab), and convalescent plasma, with promising to negative trials and other data. Non-specific immune modulators include human immunoglobulin, corticosteroids such as dexamethasone, interferons, statins, angiotensin pathway modulators, macrolides (e.g. azithromycin, clarithromycin), hydroxychloroquine and chloroquine, colchicine, and prostaglandin D2 modulators such as ramatroban. Dexamethasone 6 mg once daily (either by mouth or by intravenous injection) for 10 days may result in a reduction in mortality in COVID-19 patients by one-third for patients on ventilators, and by one-fifth for those receiving oxygen. Research efforts should focus not only on the most relevant immunomodulatory strategies but also on the optimal timing of such interventions to maximize therapeutic outcomes. In this review, we discuss the potential role and safety of these agents in the management of severe COVID-19, and their impact on survival and clinical symptoms.

Observational study of azithromycin in hospitalized patients with COVID-19

BACKGROUND

The rapid spread of the disease caused by the novel SARS-CoV-2 virus has led to the use of multiple therapeutic agents whose efficacy has not been previously demonstrated. The objective of this study was to analyze whether there is an association between the use of azithromycin and the evolution of the pulmonary disease or the time to discharge, in patients hospitalized with COVID-19.

METHODS

This was an observational study on a cohort of 418 patients admitted to three regional hospitals in Catalonia, Spain. As primary outcomes, we studied the evolution of SAFI ratio (oxygen saturation/fraction of inspired oxygen) in the first 48 hours of treatment and the time to discharge. The results were compared between patients treated and untreated with the study drug through subcohort analyses matched for multiple clinical and prognostic factors, as well as through analysis of non-matched subcohorts, using Cox multivariate models adjusted for prognostic factors.

RESULTS

There were 239 patients treated with azithromycin. Of these, 29 patients treated with azithromycin could be matched with an equivalent number of control patients. In the analysis of these matched subcohorts, SAFI at 48h had no significant changes associated to the use of azithromycin, though azithromycin treatment was associated with a longer time to discharge (10.0 days vs 6.7 days; log rank: p = 0.039). However, in the unmatched cohorts, the increased hospital stay associated to azithromycin use, was no significant after adjustment using Multivariate Cox regression models: hazard ratio 1.45 (IC95%: 0.88-2.41; p = 0.150). This study is limited by its small sample size and its observational nature; despite the strong pairing of the matched subcohorts and the adjustment of the Cox regression for multiple factors, the results may be affected by residual confusion.

CONCLUSIONS

We did not find a clinical benefit associated with the use of azithromycin, in terms of lung function 48 hours after treatment or length of hospital stay.